Honeywell 3-144, Installation Manual

Page: 21 / 90

Galaxy 3 Series Installation Manual
2-11
2. The system must be wired in a daisy-chain configuration. Spur and star configurations must not
be used as they reduce the immunity to electrical interference.
3. The cable used to connect the RS485 ( AB ) line must be screened twisted pair (Part No. W002 ) or
Belden 8723 equivalent.
4. Shielded twisted pair cable, where used, is connected to the earthing pillar on the Galaxy control
panel using the P-clip and nut supplied (refer to Figure 2-10).
5. The RS485 ( AB ) line must have a 680
Ω
resistor fitted across the A and B terminals of the last
module on the line. If twin lines are connected, both ends must be terminated with 680
Ω
resistors and
the appropriate link on the control panel PCB must be removed (refer to figure 2-9).
Figure 2-9. Twin AB Line Daisy-Chain configuration
RS485 Wiring Recommendations
To ensure that the system communicates at the maximum level of efficiency, the following recommendations
must be adhered to:
1. Each communication line can support 32 devices. The maximum number of devices on each line
are:
Table 2-5. Communication Devices
RS485 Recommendations
A
B
A
B
Galaxy
Control
Panel
680
Ω
EOL
680
Ω
EOL
A
B
Keypad/Keyprox
OR
Module
Keypad/Keyprox
OR
Module
Remove
LK3/LK5
Galaxy 3-48
(Line 1 only)
Galaxy 3-144
(Lines 1-2)
Galaxy 3-520
(Lines 1-4)
Keypads
8 8 per line 8 per line
Keyprox 3
3 (line 1)
4 (line 2) 3 (line 1)
7(lines 2, 3, 4)
RIO's/SPSU's 4 8 per line
15 (line1)
16 (lines 2, 3, 4)
Output Module
4 4 per line 4 per line
RF RIO
4 8 per line
15 (line 1)
16 (lines 2, 3, 4)
MAX 4 4 per line 8 per line
RS232
1 1 (line 1 only) 1 (line 1 only)
Telecoms
1 1 (line 1 only) 1 (line 1 only)
Printer 1 1 (line 1 only) 1 (line 1 only)
ISDN 1 1 (line 1 only) 1 (line 1 only)
Ethernet 1 1 (line 1 only) 1 (line 1 only)